Here is a demo of possible approach – use publisher with changed scrolled content coordinates with debounce, so event reported only after coordinates stopped changing.
Tested with Xcode 12.1 / iOS 14.1
UPDATE: verified as worked with Xcode 13.3 / iOS 15.4
Note: you can play with debounce period to tune it for your needs.
import Combine
struct ContentView: View {
let detector: CurrentValueSubject<CGFloat, Never>
let publisher: AnyPublisher<CGFloat, Never>
init() {
let detector = CurrentValueSubject<CGFloat, Never>(0)
self.publisher = detector
.debounce(for: .seconds(0.2), scheduler: DispatchQueue.main)
.dropFirst()
.eraseToAnyPublisher()
self.detector = detector
}
var body: some View {
ScrollView {
VStack(spacing: 20) {
ForEach(0...100, id: \.self) { i in
Rectangle()
.frame(width: 200, height: 100)
.foregroundColor(.green)
.overlay(Text("\(i)"))
}
}
.frame(maxWidth: .infinity)
.background(GeometryReader {
Color.clear.preference(key: ViewOffsetKey.self,
value: -$0.frame(in: .named("scroll")).origin.y)
})
.onPreferenceChange(ViewOffsetKey.self) { detector.send($0) }
}.coordinateSpace(name: "scroll")
.onReceive(publisher) {
print("Stopped on: \($0)")
}
}
}
struct ViewOffsetKey: PreferenceKey {
typealias Value = CGFloat
static var defaultValue = CGFloat.zero
static func reduce(value: inout Value, nextValue: () -> Value) {
value += nextValue()
}
}